kill task_detached()

Upadate the last user of task_detached(), wait_task_zombie(), to
use thread_group_leader() and kill task_detached().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Tejun Heo <tj@kernel.org>

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 0cb4f09..39acee2 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2318,11 +2318,6 @@ static inline int thread_group_empty(struct task_struct *p)
 #define delay_group_leader(p) \
                (thread_group_leader(p) && !thread_group_empty(p))
 
-static inline int task_detached(struct task_struct *p)
-{
-       return p->exit_signal == -1;
-}
-
 /*
  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
  * subscriptions and synchronises with wait4().  Also used in procfs.  Also

diff --git a/kernel/exit.c b/kernel/exit.c
index 2b1ba80..9fa9970 100644 (file)
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -189,7 +189,6 @@ repeat:
        zap_leader = 0;
        leader = p->group_leader;
        if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
-               BUG_ON(task_detached(leader));
                /*
                 * If we were the last child thread and the leader has
                 * exited already, and the leader's parent ignores SIGCHLD,
@@ -1231,9 +1230,9 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p)
        traced = ptrace_reparented(p);
        /*
         * It can be ptraced but not reparented, check
-        * !task_detached() to filter out sub-threads.
+        * thread_group_leader() to filter out sub-threads.
         */
-       if (likely(!traced) && likely(!task_detached(p))) {
+       if (likely(!traced) && thread_group_leader(p)) {
                struct signal_struct *psig;
                struct signal_struct *sig;
                unsigned long maxrss;